Cement for ships&#39; bottoms.



I06. COMPOSITIONS,

COATING OR PLASTIC.

UNITED STATES PAq i zt icn.

ADOLPH JOHANNSEN, OF FLENSBURG, GERMANY.

CEMENT FOR SHIPS BOTTOMS.

." SPECIFICATION forming part of Letters Patent No. 669,993, dated.March 19. 1901.

Application filed August 4, 1900. zlerial No. 25,894. (No specimens.) I

To all whom it may concern.-

Be it known that I, ADOLPH J OHANNSEN, a subject of the Emperor ofGermany, residing at Stiftstrasse No. 9, Flensburg, Germany,

have invented certain new and useful Improvements in Cement for ShipsBottoms; and I do hereby declare the following to be a 3 full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

It is well known that the coating of ships bottoms with a mixture ofsand and cement is very heavy, and in order to reduce the weight of themass employed for cementing the ships bottoms the cement has been mixedwith powdered coke and powdered brick or other similar material; butthis mixture has proved to be insufficient, as it is very porous,

and, on the other hand,'brittle, so that the slightest concussions ortrepidations produce cracks and seams.

The present invention is adapted to prevent this inconvenience, and hasfor its object to produce a coating for ships bottoms of less weightthan a mass which is made of cement and sand and being more resistant,and thus more useful. In order to obtain this object in view, I add to amixture of cement and 0 coke a certain quantity of fine chalk andsawdust.

The approximate proportions of the several ingredients are as follows:cement fo ty-five water is added in sufficient quantity to make up anordinary mortar, whereupon the coating can be applied and is allowed toharden 40 on the surface of the bottoms of ships. The weight of such acoating is reduced to almost one-half of the weight of the ordinarymaterial made up from cement and sand.

The addition of chalk and sawdust produces the result that even thesmallest pores of the coke are completely filled and that thus a densemass is obtained. Practical experience has shown that the adhesion tothe ships surfaces of the material above described is considerablyincreased.

I claim- As an article of manufacture, a mixture for coating shipsbottoms, composed of ordinary cement, (such as Portland or Roman) andpulverized coke to which an addition of finelypulverized chalk an finesawdust is made, substantially in the fiopmmve described.

In testimony whereof I aflix my signature in presence of two witnesses.

ADOLPH J OHANNSEN.

\Vitnesses:

J. HERMES, H. H. CLASEN.

